Nowadays, there is an increase in demand for treating water due to rising population and increased urbanization. Treatment of the water is required for obtaining healthy potable water. Therefore, there has been a demand for apparatuses and processes for obtaining fresh water from salt water or contaminated water. Contaminated and polluted ground water can be rendered drinkable through a variety of purification processes. For example, such water purification processes may include filtration, biological treatment, thermal water desalination, reverse osmosis, and distillation. Reverse osmosis processes typically produce large amounts of concentrated contaminated waste as a byproduct along with purified water. The concentrated contaminated waste may be environmentally hazardous. Further, a ratio of purified water to contaminated water decreases with increase in level of contamination in the contaminated water. Thus, the reverse osmosis process rejects a large quantity of water. Additionally, in reverse osmosis processes, contaminated water needs pre-filtration, cooling, and chemical treatment prior to being treated. Finally, membrane used in the reverse osmosis process needs a periodic replacement which is costly.
In many applications, distillation is regarded as superior to other purification processes due to usefulness of this process in distilling fresh water from salt water, and in removing toxic chemicals from contaminated water. However, a typical distillation process uses filtration operations that generate salts or contaminants as residue when the salt water or the contaminated water is converted into steam. These salts and contaminants left behind as residue cause scaling and “blow-down” in filters. Blow-down is the process that involves settling of mineral deposits in the filters. The scaling and the “blow-down” in the filters, in turn has detrimental effects on purifying ability of the distillation process. Furthermore, in order to efficiently purify the water using the distillation process, the filters require frequent maintenance to overcome the scaling and the “blow-down”.
Additionally, these distillation processes utilize thermal energy from metered energy or other expensive energy sources for converting the contaminated water into steam. Further, condensation of the steam by bringing the steam to a lower temperature to obtain a purified water also requires expensive forms of energy.
Therefore, there is a need for a method and apparatus for purifying water by reusing thermal energy derived from efficient energy sources and with less water rejects. Additionally there is a need for effective removal of contaminants that remain when contaminated water is converted into the steam.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.